Estimating the quality of a recording based on the error information

[Webturtle]

Hello,

 

How can you judge the quality of a recording based on the errors in the Info.txt file and the log file for a recording.

 

If the info file says: Errors=135, it may well be that you cannot see any errors when playing it back. This is particularly the case if the log file only contains a lot of individual errors (Errors:1). If several errors are displayed at once, then there may be problems. When recording a favorite film, you should check the time in the log to see if the recording is usable and plan to repeat it if necessary.

 

So can you tell how good a recording is based on the errors listed?

 

And what is the difference between errors and discontinuities?

 

 

Best regards

 

Webturtle

[Griga]

vor 20 Stunden schrieb Webturtle:

what is the difference between errors and discontinuities?

 

It's just a naming inconsistency in DVBViewer and basically means the same. Each gap in the sequence of received TS packets counts as 1 discontinuity or error.

 

The gaps are detected by monitoring the continuity counter in the TS packet headers, which is increased by 1 with each packet of a stream (which means, each stream or PID has a separate continuity counter). If the continuity counter value is not the expected one (usually the value of the previously received packet of a stream plus one) DVBViewer increases the discontinuity/error count by one.

 

It has to be considered that "one discontinuity" does not provide information about how many TS packets were missing (how big the gap was). It can be any number of TS packets. Furthermore it has to be considered that the continuity counter is a 4 bit (modulo 16) counter, that wraps around to 0 after having reached 15. This means, discontinuities are not detected if the number of missing packets is a multiple of 16.

 

vor 20 Stunden schrieb Webturtle:

So can you tell how good a recording is based on the errors listed?

 

You can't, because the number of errors doesn't tell you how big the gaps were and which recorded stream (video, audio, service information data, EPG, teletext, subtitles..) and which part of the data was affected. It may be a less or more important part. Furthermore the impact on playback depends on the error concealment abilities of playback components (also video hardware decoders). They may hide gaps well so that you don't notice them anymore. If they don't recognize the gaps or can't hide them, because they are too big, you will perceive jerks and/or artefacts. Usually video is affected with highest probability, because the lion's share of recorded data is video, thus providing the largest "attack surface".

 

The number of discontinuities/errors is just a rough indicator for how much a recording may be damaged due to data that has arrived incompletely. It indicates more or less data loss in the DVB device driver  or a network or due to bad reception, causing more or less playback disturbances.